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<h2><a name="SECTION0027920000000000000000">
25.9.2 Examples</a>
</h2>

<p>
Here are two example sessions (one using the command line, one using
the module interface) that compare the cost of using
<tt class="function">hasattr()</tt> vs. <tt class="keyword">try</tt>/<tt class="keyword">except</tt> to test for
missing and present object attributes.

<p>
<div class="verbatim"><pre>
% timeit.py 'try:' '  str.__nonzero__' 'except AttributeError:' '  pass'
100000 loops, best of 3: 15.7 usec per loop
% timeit.py 'if hasattr(str, "__nonzero__"): pass'
100000 loops, best of 3: 4.26 usec per loop
% timeit.py 'try:' '  int.__nonzero__' 'except AttributeError:' '  pass'
1000000 loops, best of 3: 1.43 usec per loop
% timeit.py 'if hasattr(int, "__nonzero__"): pass'
100000 loops, best of 3: 2.23 usec per loop
</pre></div>

<p>
<div class="verbatim"><pre>
&gt;&gt;&gt; import timeit
&gt;&gt;&gt; s = """\
... try:
...     str.__nonzero__
... except AttributeError:
...     pass
... """
&gt;&gt;&gt; t = timeit.Timer(stmt=s)
&gt;&gt;&gt; print "%.2f usec/pass" % (1000000 * t.timeit(number=100000)/100000)
17.09 usec/pass
&gt;&gt;&gt; s = """\
... if hasattr(str, '__nonzero__'): pass
... """
&gt;&gt;&gt; t = timeit.Timer(stmt=s)
&gt;&gt;&gt; print "%.2f usec/pass" % (1000000 * t.timeit(number=100000)/100000)
4.85 usec/pass
&gt;&gt;&gt; s = """\
... try:
...     int.__nonzero__
... except AttributeError:
...     pass
... """
&gt;&gt;&gt; t = timeit.Timer(stmt=s)
&gt;&gt;&gt; print "%.2f usec/pass" % (1000000 * t.timeit(number=100000)/100000)
1.97 usec/pass
&gt;&gt;&gt; s = """\
... if hasattr(int, '__nonzero__'): pass
... """
&gt;&gt;&gt; t = timeit.Timer(stmt=s)
&gt;&gt;&gt; print "%.2f usec/pass" % (1000000 * t.timeit(number=100000)/100000)
3.15 usec/pass
</pre></div>

<p>
To give the <tt class="module">timeit</tt> module access to functions you
define, you can pass a <code>setup</code> parameter which contains an import
statement:

<p>
<div class="verbatim"><pre>
def test():
    "Stupid test function"
    L = []
    for i in range(100):
        L.append(i)

if __name__=='__main__':
    from timeit import Timer
    t = Timer("test()", "from __main__ import test")
    print t.timeit()
</pre></div>

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